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L. PASTEUR.

Manufacture of Beer and Yeast.

Patented July 22, 2873.

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UNITED STATES PATENT OFFICE.

LOUIS PASTEUR, OF PARIS, FRANCE.

IMPROVEMENT lN-THE MANUFACTURE OF BEER AND YE-AST.

Specification forming part of Letten Patent No. 141,072, dated 'July22.11673; eppliostlon Med May 9, i873.

To all whom it may concern:

Be it known that I, Louis PASTEUR, of Paris, France, have inventedImprovements in the Manufactum and Preservation of Beer and in theTreatment of Yeast and Wort, to gather with Apparatus for the same; andI do hereby declare that the following is a full, clear, and exactdescription of the same, reference being had to the annexed sheet ofdrawings, making a part of the same.

The variations iu the condition of brewers yeast, worte, andv beer, arecaused by the presence of microscopic organisms, the devoiopment andmultiplication of which are accompanied by the. formation of substanceswhich change the properties of the wort, beer or yeast, and alsoIin'event it keeping beyond a certain time. bese organisms exist invarying proportions in cooled worte, as prepared by the ordinaryprocesses, as well ne in `yeast and beer.

The object of this invention is to eliminate und prevent themultiplication of these organisms by the following means, viz: First,obtaining pure yeast by separating 'the organic germs foreiglrtobrewers' yeast; second, treating the Wort while cooling 'from the timeit leaves the copper, in which all the germs of disease are destroyed,until it reaches the vate, tuus, 0r fcrnienting apparatus, and

even after ferment-ation in such manner that it shall not again receveither by unlimited contact with the open air or with the vesselsemployed, any pernicious gems capable oi multiplying and of subsequentlychanging the condition of the product; third, cooling in closed vesselsiu the presence of a limited supply of filtered air or carbonieacid gas.

Pure yeast, free from pernicious germs, muy be obtained in various ways,among which I will indicate the following: I take impure yeast and causeit to act on n solution of sugar-candy in pure water. When thefermentation is terminated, I lecant the fermentod liquid und add afresh quantity of angered water on the top of the yeast deposit. Thisoperation h1 re ated two or time ti more or less, ecco ing locircumstances.

then take a shallow porcelain dish, rst di iping it in boiling water,and put in it a lit e beer wort which has been recently boiled orpreserved by the Appert process. I then dilute a little of the yeast det of the abovedescribed fermentation in t e `wort, und cover it with aglass plate. The yeast, which has become more or less exhausted byits-action on the su water, will then rise and rapidly revive, puritledof all germs of disease.

This treatment may be repeated by diluting a little of the yeastdeposited at the bottom of the nrst dish in some fresh wort.v

The degree of purity of the yeast may bc ascertained with the aidl of lamicroscope, which will indicate the presence of the and show whether, bmeans of the yeast, a' beer may be produ which shall not vary incoidittlilou et any teFm n c diagram ing drawing, the iett of thetlgureshows a pure nico olio yeast, and the other half au alcoholicyeast containing the diseased germs,

which are iiliform in appearance. For this p I take n balloon, of .theform shown in ig. 2, otany suitable dimensions, and about half ll itwith beer wort, which is rst rende balloon itself. The neck A B visclosed by an Indiivmbber tube, b' c', and a glass plug, 0 D. The plug isremoved, and one or more drops ofthe yeast from the dish, diluted withalittle of the snperuatantli ui is introduced by means of the tube M wich fel-ments` the wort and transforms it into beer.

it' this beer, ser remaining somefweeks 1u a stove having a temperatureof from 10 to 80 Fahrenheit be examined under the Inicio` scope and nogerms of disease can be perceived, it will show that the :mail quantity:if yeast intmduced wus perfectly free thererom.

With yeast thus obtained large quantities may be prepared, it beingne'mted during the manufacture of the beer teelt'. Yeast muy also bepreserved iudeniteiy in a pure state in contact with pme air-that is tosay, ein

which has been lmrged ol all diseased genna 1 ofthe acoompany- I reduualterable by being boiled in tbe Vliable to afect' the condition ofthe yeast, either in an apparatus such as thatshown in Fig. 2, or othersimilar arrangement. .It may 9180 be carried long distances withoutatiectlng its condition, and so serve for preparing lml yeast at allseasons and in any quantity desired By this means -the brewer will bespared the necessity of obtaining a fresh snpply of yeast from a brewerywhen his own has me deteriorated, inasmuch as he has always yeast at hisdisposal in au ever pure coudition.

Alcoholic yeasts, which are .properly distinct, may also be propagatedand cultivated,'

without becoming altered, by the aid of 'the apparatus shown in 2.

will next describe eimproved process of manufacturing and preservingbeer, and preparing yeast exempt from diseased germs on any desiredscale.

I use the apparatus, Fi 3, consisting of a. cylindrical vessel, clo by ncover, the nm of which dips into a water-trough around the top of thevessel, provided with a cock, 1 The heer-wort, properly so called, orother wort used iu beer-making, is tlrst boiled in the copper, and thenpoured into the cylinder, which is completely filled, and the cover puton. Then, by means of a rubber tube,.c d, the metal pipe a c, openinginto a stoppered pipe rising from the. cover, is counected with the.tube d c f g. Boiling water is then poured on tho cover and on the pipesrislxig therefrom, which fills the trough, the ov ow passing inte agutter, i ,from which the water escapes through a slit or a number ofsmall holes in the bottom, and is collected in another gutter at thebottom of the cylinder, provided with a dischargcpipe` M.

T is a bent thermometer, for indicating the temperature of the wort, thebulb of which s'pmtected by a perforated guard, d d. R V are cocks orapertures for discharging the liquid and sediment from the cylinder.

The cylinder thus tilled is allowed'to cool by contact of the-externalair, afterward assisted, if n by cold water introduced at pipe E on thecover, whichpasses through apertures e e, and trickles down o'ver thecylluder. Air enters the long tube g off d ca. The east is thenintroduced through the pipe ,which is immediately closed, the carbonicacid produced during the fermentation Atu similartoacdcfgmaybeadapted topipe D, of a dierent length if desired, for the wap@ nf the mantenutigu, while a limited quantity of nir is admitted by the other tube.

, The wort may be readily. cooled in presence of carbonio acid gas byintroducln itine latter beneath the cover during the g. 'Ihe tube f gmay terminate by s loose plug of ssbestus or. cotton, or by a metal tubeheated during the admission of the air. A drop of liquid in bend g willserve to indicat the movements of the gases.

The apparatus may be greatly varied in form, and any apparatus whichwill serve to eliminate the germs of disease, derived either from theair, the raw materials, the yeast, or the apparatus itself, will answerthe purpose.

The employment of pure yeast in the above process is of rimenecessity-that is to say, yeast depriv of the germs by which the beer isliable to be a'ected.

A ll kinds of beer manufactured by this process may be preserved withoutthe aid of ice, and may be made in hot as well as cold climates, assummer as in winter.

As there is no liability of the worts undergoing any change a very smallquantity of pure yeast will be sutllcient to ferment it.

The following is a recapitulatiou of the es sential features of this imroved process: The wort is introduced in a iling state iuw theapparatus, on which a cover is then placed, or the cvlinder may beentirely closed and communicate with the atmosphere only by means of thepipes, cocks, and long tubes with which it is provided. Boiling water isthen thrown on the a paratns, alter which 1t is allowed to cool witg orwithout the assistluce of cold water,.during which time air orvcarbonio-acid gas is .admitted by the long tube 'g de f c a; butprevious to this one of the plp on the cover is closed by unplug,through which passes a tube, terminating in an India rubberA tube andglass stopper. Pure wort is then fermented by pure yeast, and, whensufficiently advanced, the contents are poured .through the tube in thestopper of the pipe on the cover of the fermenting apparatus.'

1f there is a supply of pure yeast from the preceding operation this maybe used, as in the ordinary processes, the vessel being unetvered forthe purpose, it' necessary, after fermentation has commenced; but thismight lead to great inconvenience at a subsequent period, although theuse of pure yeast, mannfactured according to this limproved process,would o( itself form a great improvement on the'ordinary p.

With the aid of the microscope andthe method ot' control, beforelndicated,thc change of condition, which might arise under the lat termodes of treatment, may bc readily sscertained; but one coolingapparatus v be used or a few, only the wort being p 1;- into vets,-(pitched or varnished on the extenor,) which are deprived of any germsof disease, either by the use of boiling water orby s re cent ng ofpitch on the interior.

It-wl be seen that the ordinary and the improved method, may, l desired,

mums a be earried on simultaneously, so that nrewers will be enabled togradually transform their plant.

After the beer is made any short exposure in the air, to which it may besubjected, will have little or no Xrejudicial elect on its keepingqualities, an it may also be lined in the usual way.

I claim- Y '1. The method of obtaining pure yeast by eliminating theorganic germs of disease fromA brewers yeast, in the manner described.

2. Yeast, free from organic germs of disesse, as an article ofmanufacture.

3. The vessel, having neck A B, rubber -tube b! e' and glass plug 0 D;as and for the purpose escribed.

.4. The apparatus, consisting essentially of e covered vessel havingwater-trough around the top. rubber tube e d, metal ipe a, tube dfg, topand bottom gutters, un pipes D E, together with suitable cocks,thermometer, outlets, and inlets, substantially as set forth.

IDUIB PASTEUXL 0mm DnLUos, Anonym-1 Gmox.

